https://gcc.gnu.org/bugzilla/show_bug.cgi?id=71182
--- Comment #4 from Markus Trippelsdorf <trippels at gcc dot gnu.org> --- (In reply to Richard Biener from comment #3) > Can't reproduce on trunk or GCC 6 branch. What options are required? You need to use an -fsanitize=undefined instrumented compiler. No options required.